Muscovite is commonly found in a variety of rock types including granites, pegmatites, schists, gneisses, marbles, quartz veins, and some metamorphic and igneous rocks. Pegmatites, which are coarse-grained igneous rocks formed from magma, are significant sources of muscovite as they often contain large, well-developed muscovite crystals. Other regions rich in muscovite include areas with notable geological formations composed of metamorphic rocks containing mica. For example, significant muscovite deposits occur in areas like Brazil, the Ural Mountains, Madagascar, India, Canada, Russia, Afghanistan, and several African countries.